The present invention relates, in general, to electronics, and more particularly, to methods of forming semiconductor devices and structure.
In the past, the semiconductor industry utilized various methods and structures to form switching power supply controllers that regulated the value of an output voltage of a power control system. In some applications, the power to operate the switching power supply controller was derived from an auxiliary winding of a transformer. In such an application, the amount of power consumed by the switching power supply controller was greater than a desired value. Additionally, in some cases the range of the input voltage to the switching power supply controller was limited which reduced the useful operating voltage range of the switching power supply controller.
Accordingly, it is desirable to have a switching power supply controller that has reduced power dissipation, and that facilitates a wider operating range of the input voltage.
For simplicity and clarity of the illustration, elements in the figures are not necessarily to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. As used herein current carrying electrode means an element of a device that carries current through the device such as a source or a drain of an MOS transistor or an emitter or a collector of a bipolar transistor or a cathode or anode of a diode, and a control electrode means an element of the device that controls current through the device such as a gate of an MOS transistor or a base of a bipolar transistor. Although the devices are explained herein as certain N-channel or P-Channel devices, a person of ordinary skill in the art will appreciate that complementary devices are also possible in accordance with the present invention. It will be appreciated by those skilled in the art that the words during, while, and when as used herein are not exact terms that mean an action takes place instantly upon an initiating action but that there may be some small but reasonable delay, such as a propagation delay, between the reaction that is initiated by the initial action.